Self-locking and self-sealing nail



March l5, 1966 R, L, HALLQCK 3,240,101.

SELF-LOCKING AND SELF-SEALING NAIL Filed July 22, 1965 F INVENTOR ROBERT L. HALLOCK United States Patent 3,240,101 SELF-LOCKING AN D SELF-SEALING NAIL Robert L. Hallock, Chatham, Mass., assigner to Elastic Stop Nut Corporation of America, Union, NJ., a corporation of New Jersey Filed July 22, 1963, Ser. No. 296,644 2 Claims. (Cl. 85-23) This invention relates generally to self-locking nails, and more particularly to an improved self-locking, selfsealing nail having a pair of channel-shaped Shanks, at least one of which is deformable. The self-locking, selfsealing nail of the present invention is particularly useful in the fastening of the rooting base sheet of felt to low density roof decks to guard against pitch drippage.

The nail of the present invention relates to sheet metal nails of the general character provided with two adjacent legs or Shanks of channel form connected at the head end by a collapsible head which is collapsed when the nail is driven home to cause relative longitudinal movement between the two legs. The legs interengage at a point intermediate their ends and are otherwise so constructed that the lower or foot portion of one of the Shanks is bent outwardly to a position approximately at right angles to the axis of the nail. More particularly, the present invention is an improvement upon the kinds of nails disclosed in U.S Patents Nos. 2,603,121, granted July l5, 1952 and 2,741,939, granted on April 17, 1956 to the inventor of the present invention.

Nails of the kind disclosed in the aforesaid patents have become widely used in building construction of the kind in which the commonly used wood roofing has been replaced by insulating and other types of artificial wall boards, usually of cellulosic fibrous material or of gypsum or other mineral substance or mixtures, a common characteristic of which is inability to provide holding power for ordinary nails.

While nails of the kind disclosed in the aforesaid patents have proved to be highly successful commercially in many applications, it has been found necessary to seal the hole through which the nail is driven and to seal the space between the Shanks of the nail when used on certain roofs in relatively hot climates. This is desirable because, in southern climates and on relatively hot days, the pitch or tar on the roof melts and runs down the nail shanks and through the porous roof materials, Such as Insulrock or Tectum and artificial liber boards.

It is an object of the present invention to provide an improved self-locking nail that is provided with means for sealing the hole caused by the nail and the space between the shanks of the nail.

It is another object of the present invention to provide an improved Self-locking nail that is provided with sealing `means within a collapsible head whereby to seal the space `between adjacent Shanks of the nail.

Still another object of the present invention is to provide an improved self-locking nail with an auxiliary head that is adapted to be secured snugly beneath the collapsible head of the nail for preventing the Shanks of the nail from separating at the head end when the nail is driven home.

A further object of the present invention is to provide an improved self-locking nail of the type described that is relatively simple in construction, easy to manufacture, and highly eiicient in use.

Briefly stated, the improved self-locking, self-sealing nail of the present invention comprises a pair of Shanks of channel form connected at the head end of the nail by a collapsible head. The Shanks are secured to the head in a manner whereby relative movement is caused between the Shanks when a nail is driven home. The shanks are interengaged in a manner whereby the lower portion of 35,240,101 Patented Mar. 15, 1966 one of the Shanks is caused to bend laterally from the shank axis when the nail is driven home. A foam plastic is disposed within the head and between the two Shanks of the nail so as to seal any opening or space that may exist between the Shanks when the nail is driven home. A cap of sheet metal is disposed tightly about the underside of the head of the nail by means of downwardly and inwardly extending flanges that define an opening through which the Shanks of the nail extend. When the nail is driven home the cap prevents the upper portions of the two Shanks from spreading, thereby enabling the foam plastic to seal the space between the Shanks when the head is collapsed. The cap also helps to cover and seal the hole through which the nail passes.

IOther and more detailed objects will appear as the en* suing portion of this specification proceeds with the description of a preferred embodiment of nail, disclosed by way of example but without limitation, to which reference may be had in conjunction with the accompanying drawings forming a part hereof, in which:

FIG. l is a plan view of a sheet metal blank from which the nail is made;

FIG. 2 iS an elevation of a nail formed. from the blank shown in FIG. l and illustrating a novel cap engaging the collapsible head of the nail;

FIG. 3 is a section taken on the line 3--3 of FIG. 2 and showing foam plastic material Within the collapsible head of the nail;

FIG, 4 is an enlarged fragmentary view of a part of the nail shown in FIG. 2;

FIG. 5 is an enlarged fragmentary section of the part of the nail shown in FIG. 3;

FIG. 6 is a section taken on the line 6 6 of FIG. 5;

FIG. 7 is a section taken on the line 7 7 of FIG. 5;

FIG. 8 is a section showing the nail after being driven into soft artificial material, permitting the foot of the nail to bend outwardly; and

FIG. 9 is a section taken on the line 9-9 of FIG. 2, and showing a plan View of the novel nail cap.

Referring now more particularly to FIG. l of the drawings, lll indicates a blank of thin at sheet metal for facing nails of the kind previously mentioned. It is advan tageously of stainless steel. At one of its ends, the blank is cut to provide a sharp V-shaped point l2, and for manufacturing and material saving reasons, the opposite end is cut to generally V-shaped form as shown at 14, there being a small reentrant notch 16 at this end left by the point 12 of the next succeeding blank l0, shown in dotted lines, the blanks being cut from a continuous strip or skelp of Sheet material. So far as the functioning of the nail is concerned, the particular configuration of the generally pointed end 14 is not critical.

Adjacent to the pointed end 12 of the nail, the metal is sheared to form a longitudinally extending finger-like tongue 26 pointed at its free end and bent downwardly from the plane of the blank.

Adjacent to the other end 14 of the blank, a second finger-like tongue 3u pointed at its end and pointing away from the adjacent end ld of the blank is provided. This tongue is both longer and wider than the tongue 26 and is also bent away from the plane of the blank on the same side as the tongue 26.

An elongated aperture 29 is formed in the blank at the bending line 22. The aperture 29 extends longitudinally of the blank along the central axis thereof for the purpose hereinafter appearing.

By suitably bending and forming operations of known character, and forming no part of the present invention, the blank just describe-d is bent back upon itself to form a nail as shown in FIGS. 2 through 7. As shown in these figures the end portions of the blank, at each side of the ice a bend lines and 24, are bent to channel form to provide the two channelled legs or Shanks 32 and 34 of unequal length, the longer shank 32 constituting the driving shank of the nail and the shorter constituting the holding shank. The blank is bent at the bend lines to form a head 36 comprising top and bottom parallel plates joined by flat plate portions 36a and 36h to form a at driving surface and a flat bottom contact surface to resist pressure developed when attening the head connected respectively to the Shanks 32 and 34 and angularly related to form a head extending laterally to one side of the axis of the nail. The formation of the Shanks to channel form, while retaining a tiat plate-like form of the head is facilita-ted by the sheared lines 20a and 2011 along the line 2lb and by the sheared lines 24a and 24b along the line 24. This is done to make a true column of the driving leg, i.e., a ii'at top surface for the top portion of the head to rest on. This greatly increases the column strength of the driving leg.

As shown, the Shanks are bent into parallel adjacent relation, with the channel portion of the shorter or holding shank nested in the channel of the longer or driving shank. As seen more particularly in FIG. 6, the channels are made relatively sharp and deep, with the webs of the channels forming between them a sharply acute angle.

As appears more clearly from FIGS. 4 and 5, the bent tongues 26 an-d 30 are brought into overlapping interengagement, the tongue 26 projecting into the opening created by the forming of tongue 30, and the tongue 3% projecting into the opening created by the formation of tongue 26.

A foam plastic P is formed within the head 36 and between the upper portions of the Shanks 32 and 34, as shown in FIGS. 3 and 9, for the purpose hereinafter appearing.

From a place just above the tongue 3@- on the holding shank 34, the outer edges of the webs of the channel are iiared outwardly to provide ligaments 34a and 34h which extend across the edges of the webs of the channel of the driving leg 32 and lie in a plane at right angles to the median plane of the nested channels. As will be Seen more particularly from FIG. 4, these ligaments lie at either side of the tongue 30.

In accordance with prior practice, the pointed or penetrating end 12 at the driving shank is olf-set slightly so that that point is in alignment with the base or root of the channel of the holding shank 34, the penetrating end portion 12 of the driving shank thus substantially masking the end 14 of the holding shank.

An auxiliary head, or cap C, of sheet metal is disposed under the head 36 of the nail. The cap C is secured tightly against the Shanks 32 and 34 by anges F that extend downwardly and inwardly from portions of the cap C, the flanges F detining a somewhat triangular hole 35, as shown in FIG. 9.

Turning now more particularly to FIG. 8, the nail just described is shown after being driven in a typical application wherein one or two layers of roong felt 38, are secured to a board 42 of relatively soft artificial material, such as insulrock, tectum or gypsum.

When driving the nail in such an application, the two Shanks remain in their parallel ixed relationship, without relative movement, until the lower surface of the cap C strikes the face of the rooting felt. Thus, the cap C, when against the felt 3S, acts as an abutment preventing further inward or penetrating movement of the holding shank, as shown in FIG. 8. As the nail is driven home the head collapses, this being facilitated by the aperture 29 and sheared lines 20a, 2919, 24a and 2411, the collapse of the head being accompanied by relative longitudinal movement between the driving and holding Shanks, the former moving toward the head end ot the nail relative to the latter as the head collapses. This relative movement causes the portion of the holding shank below the interengaging tongues 26 and 3i), which constitutes the foot portion of the shank, to be bent outwardly away from the driving shank with a pivotal movement about the tongue 26 as a fulcrum point.

Due to the sheared-out tongue 30, which advantageously at its base is substantially as wide as the channelled portion of the foot, thus leaving only the two at and relatively narrow ligaments S-/a and 3417, a place is provided in the holding shank where the foot joins the upper por* tion of the shank that is relatively very weak in resistance to bending as compared with the remaining portions of the Shank. As will be observed from FIG. 5, the fulcrum point 4established by the interengaging tongues 26 and 3@ is displaced laterally a substantial distance from the plane of the ligaments 34a and 34b, so that when rela tive movement between the Shanks occurs a force acting through a Substantial moment arm is applied to the ligaments to bend them and cause the pivotal movement of the foot.

The disposition of the ligaments with respect to the plane of the bending provides for an improved and more reliable bending than in previous nails operating in accordance with the Same general principle. From FIGS. 4 and 7, it will be seen that the plane of the ligaments is at right angles to the plane of bending, and, consequently, the required bends are made across the rolled surface of the metal. The result is that the bend can be effected with less strain being developed in the material and less likelihood of fracture at the bend point, as compared with a bending action in which the bend is made substantially in he plane of the material at right angles to the rolled suraces.

As will also be seen from the drawings, the ligaments 34a and 34b result in the formation of a foot portion which is wider laterally than would be the case if these ligaments were not provided, thus giving greater bearing area for the root.

The -bottom ends of the ligaments are sheared and not bent outward so as to form iishhooks 40. These hooks cling to the material 42 to increase the holding power of the nail.

If the cap C were not used, the upper portions of the Shanks 32 and 34 may tend to separate somewhat, especially if the material 42 is relatively dense. By incorporating the cap C directly underneath the head 36 of the nail and by having the flanges F (that define the hole 35 in the cap C) press against the Shanks 32 and 34, the cap C forms an auxiliary head for the nail and functions to Seal the hole through which the nail penetrates, in addition to preventing Shanks 32 and 34 from separating. The foam plastic P, being disposed within the head 36 and between the upper portions of the Shanks 32 and 34 is compressed when the nail is hammered home so as to seal any space that may exist between the Shanks 32 and 34. Also, some of the foam plastic P may be squeezed into the hole formed by the nail when the head 36 is collapsed, thereby helping, in cooperation with the cap C, to seal the hole formed by the nail. The foam plastic P may also be disposed on the lower head portion, if desired, to seal holes in especially soft material.

The foam plastic P can be placed within the uncollapsed head 36 and between the upper portions of the Shanks 32 and 34, as shown in FIGS. 3 and 9, by dipping the head of the nail into a foam forming liquid which, when heated, turns into a sponge rubber-like material. Foam plastic forming liquids can also be squirted into the head portion 36 and between the Shanks 32 and 34 through the aperture 2.9 in the head 36.

Suitable solutions for providing the foam plastic P, either at room temperature or when heated, are available commercially. A satisfactory plastic foam producing solution for use in the present invention is provided by Minnesota Mining & Manufacturing Co.

Another suitable solution for producing a resilient, sponge-like foam plastic P, that may be applied to the nail head by either spraying or dipping is sold by M & T Chemicals, Inc., Rahway, NJ. under the trade name of Unichrome Plastison 4417. After dipping, for example, the foam plastic is cured by infrared heat for ve minutes at 360 F.

Mixtures of an isocyanate resin, 120% of a plasticizer, such as dioctyl phthalate, and 35-70% of a filling resin, such as phenol or epoxy, with a film forming oil form suitable plastic foams at room temperature. For example, a mixture of 45 parts oiticicia oil, 4 parts dioctyl phthalate and 51 parts of a mixture of isocyanate and epoxy resins provide a foam forming mixture which provides a low density foam at room temperature.

Another example of a suitable foam plastic for use in the present invention may be formed from a mixture of 100 parts of a copolymer, made of 196y parts of methyl acrylate and 11.6 parts of allyl alcohol. The latter is mixed with parts toluene diisocyanate and heated at 90 degrees C. for 45 minutes. When mixed with one part H2O, the product foams and yields a foam plastic of low density.

.Suitable polyurethane foam plastics for use in the present invention are disclosed in the U.S. Patent No. 2,895,926 granted on July 21, 1959 to G. Rappaport, A. Szaruga and J. R. Wall. Other suitable polyester-polyisocyanate foams for the present invention that foam at room temperature are available.

From the foregoing description, it will be apparent that there has been provided an improved self-locking, Self-sealing nail wherein an auxiliary head, or cap, is secured beneath the collapsible head of the nail to prevent the Shanks from `spreading when the nail is driven home, and a foam plastic material which seals the space between the upper portions of the Shanks. The cap and the foam plastic also function to seal the hole caused by the nail in the material into which it is driven.

While for the purposes of disclosure a preferred example has ben described and illustrated, it will be apparent to those skilled in the art that the specific design may be modified in numerous ways without departing from the principles of the present invention. The foregoing description, is therefore, intended to be illustrative, and is not to be considered in a limiting sense.

What I claim is:

1. In combination, a nail formed from a sheet of metal and comprising a driving shank, a holding shank adjacent to said driving shank and located relative thereto such that a void is established -between the Shanks, said holding shank being laterally bendable and said driving shank being pointed at the penetrating end of the nail and relatively rigid against lateral bending, a collapsible head connecting said Shanks at the head end of the nail, said head comprising an upper driving portion connected to said driving shank and providing a striking surface adapted to be struck by a tool to drive the nail,

and a lower abutment portion integral with and laterally displaced from said driving portion and connected to said holding shank thereby defining a hollow space within the head, said lower abutment allowing said head to be collapsed when the nail is driven home and thereby producing relative longitudinal movement between the Shanks, said holding shank having a relatively weak portion intermediate its ends for establishing a predetermined bending place in the shank, means comprising a projection on said holding shank and a cooperating aperture on said driving shank into which said projection extends to engage the driving shank and provide a fulcrum point about which the penetrating end portion of said holding shank is caused to bend laterally away from the driving shank upon said relative movement between the Shanks whereby said holding shank will move laterally away from said driving shank and said void will be enlarged, and sealing material in said void between the Shanks and in said hollow space in Said head, said sealing material comprising a foamed thermosetting synthetic resin placed in said void and said hollow space as a liquid containing a foaming agent and expanded in situ to establish a foamed thermosetting synthetic resin mass adhered to portions of said head of the nail and between at least the upper portions of Said Shanks and held in compression thereby such that at least a portion of said mass of sealing material in said head is forced. -between said upper shank portions to aid in sealing any space therebetween when the nail is driven home.

2. The combination defined in claim 1 and including a cap formed with an aperture therein for receiving said Shanks therethrough and Said abutment portion of said head against a surface thereof, Said cap providing an abutment against which said head will collapse when the nail is driven home and said aperture laterally confining at least the upper portions of said Shanks to limit the relative lateral -movement of said Shanks and the en largement of said fvoid between the Shanks when the nail is driven home.

References Cited by the Examiner UNITED STATES PATENTS 964,226 7/ 1910 Ferrand 85-31 1,814,502 7/1931 Barwood 85-50 2,429,113 10/1947 Warner 85--11 2,439,516 4/ 1948 Holcomb 85-28 2,603,121 7/1952 Hallock 85--11 2,687,666 8/1954 Chalfont et al. 85-11 2,724,303 1l/1955 Holcomb 85--50 2,741,939 4/1956 Hallock 85-23 2,765,834 1071956 Poupitch.

2,927,495 3/ 1960 Barwood 85-50 CARL W. TOMLIN, Primary Examiner.

EDWARD C. ALLEN, Examiner. 

1. IN COMBINATION, A RAIL FORMED FROM A SHEET OF METAL AND COMPRISING A DRIVING SHANK, A HOLDING SHANK ADJACENT TO SAID DRIVING SHANK AND LOCATED RELATIVE THERETO SUCH THAT A VOID IS ESTABLISHED BETWEEN THE SHANKS, SAID HOLDING SHANK BEING LATERALLY BENDABLE AND SAID DRIVING SHANK BEING POINTED AT THE PENETRATING END OF THE NAIL AND RELATIVELY RIGID AGAINST LATERAL BENDING, A COLLAPSIBLE HEAD CONNECTING SAID SHANKS AT THE HEAD END OF THE NAIL, SAID HEAD COMPRISING AN UPPER DRIVING MOTION CONNECTED TO SAID DRIVING SHANK AND PROVIDING A STRIKING SURFACE ADAPTED TO BE STRUCK BY A TOOL TO DRIVE THE NAIL, AND A LOWER ABUTMENT PORTION INTEGRAL WITH AND LATERALLY DISPLACED FROM SAID DRIVING PORTION AND CONNECTED TO SAID HOLDING SHANK THEREBY DEFINING A HOLLOW SPACE WITHIN THE HEAD, SAID LOWER ABUTMENT ALLOWING SAID HEAD TO BE COLLASPED WHEN THE NAIL IS DRIVEN HOME AND THEREBY PRODUCING RELATIVE LONGITUDINAL MOVEMENT BETWEEN THE SHANKS, SAID HOLDING SHANK HAVING A RELATIVELY WEAK PORTION INTERMEDIATE ITS ENDS FOR ESTABLISHING A PREDETERMINED BENDING PLACE IN THE SHANK, MEANS COMPRISING A PROJECTION ON SAID HOLDING SHANK AND A COOPERATING APERTURE ON SAID DRIVING SHANK INTO WHICH SAID PROJECTION EXTENDS TO ENGAGE THE DRIVING SHANK AND PROVIDE A FULCRUM POINT ABOUT WHICH THE PENETRATING END PORTION OF SAID HOLDING SHANK IS CAUSED TO BEND LATERALLY AWAY FROM THE DRIVING SHANK UPON SAID RELATIVE MOVEMENT BETWEEN THE SHANKS WHEREBY SAID HOLDING SHANK WILL MOVE LATERALLY AWAY FROM SAID DRIVING SHANK AND SAID VOID WILL BE ENLARGED, AND SEALING MATERIAL IN SAID VOID BETWEEN THE SHANKS AND IN SAID HOLLOW SPACE IN SAID HEAD, SAID SEALING MATERIAL COMPRISING A FOAMED THERMOSETTING SYNTHETIC RESIN PLACED IN SAID VOID AND SAID HOLLOW SPACE AS A LIQUID CONTAINING AND FOAMING AGENT AND EXPANDED IN SITU TO ESTABLISH A FOAMED THERMOSETTING SYNTHETIC RESIN MASS ADHERED TO PORTIONS OF SAID HEAD OF THE NAIL AND BETWEEN AT LEAST THE UPPER PORTIONS OF SAID SHANKS AND HELD IN COMPRESSION THEREBY SUCH THAT AT LEAST A PORTION OF SAID MASS OF SEALING MATERIAL IN SAID HEAD IS FORCED BETWEEN SAID UPPER SHANK PORTIONS TO AID IN SEALING ANY SPACE THEREBETWEEN WHEN THE NAIL IS DRIVEN HOME. 